I have both (although only Berlin legacy), I think a better way of putting it is to say the Spitfire legatos have more character... they are more lyrical, especially in the solo instruments. In practice, that can get in the way. In a mix, I find sometimes the Spitfire legato can sound odd, and result in the instrument being inaudible in parts of the phrasing. They also can jump around a bit in the smoothness of the room tone when more exposed. You really need to work the mod wheel to try overcome the built in phrasing issue if it fighting against you, and sometimes that just doesn't work. The Berlin woods you don't have this problem. For very exposed work with Berlin, where the less lyrical legato doesn't work for you, that's where you'd move to the Berlin expansions. So while I don't disagree, and plenty of this is personal taste anyway, I think it may not be as straight forward as you might think.